Broken-tap extractor



Patented Sept. 11,1928.

Davin runner, or Los enemas, oamronnm;

BROKEN-TAP nx'rneo ron.

"Application filed October 14, 1928. Serial No.141gi54 My invention relates to a broken tap extractor and has torvits principal object the provision of a relatively simple and practical tool or implement that may be advantageous- 5 1y utilized fortheextraction of those portrons of broken-taps'that are embedded in the work. i

It will be understood that inthreading apcrtures in metal, the taps used for "formmg the threads,

result that a portion of thetap is embedded in the metal and the removal of the broken portion involves considerable time and labor.

I propose to provide a relatively small tool having teeth on one end for countersinking the hole in which the broken tap is positioned and the other end of the tool being constructed so as to engage the end of the broken tap and function as a Wrench to unscrmv the broken portion of the tap.

With the foregoing and other objects in view, my invention consists in certain novel features of construction and ar *angement of parts that will hereinafter be more fully described and claimed andillustrated in the accompanying drawing, in which- Fig. 1 is a side elevational View of a broken tap extractor of my improved construction.

Fig. 2 is an elevational view of that end of the extractor that is utilized for countersinking the hole in which the broken tap is positioned. v

Fig. 3is an elevational view ot that end of the tool that is utilized as a Wrench in removing the broken portion ofthe tap.

Fig. 1 is an enlarged section showing the tool in position whilejthe hole in the vvork V is beingcountersunk.

Fig. 5 is a sectional View showing the wrench end ot'the tool in positionadjacent to the end of the broken port-ion of the tap.

Referring by numerals to the accompanying drawing, which illustrates a practical embodiment of my invention, 10 designates the body of my improved broken tap extractorwhich body comprisesa short metal rod of hardened metal-such as high speed steel. One end of the body of the tool is provided with a short longitudinally disposedrecess 11 and the terminal portion of the wall 12 surrounding said recess is beveled oil on its outer corner as designated by 13 and the beveled portion of said Wall is slotted len thwise so as Z3 to form an annular row ot metal cuttlng teeth 14.

formed in the surfaces of ti and particularly the smaller sizes 0t taps, very trequently break with the he opgosite end of the l ded with a short lor.

L of longitudinally usribs in that are arranged approximatelv 90 apart they com the iongitudinaliy disposed r m that are o --1( music o ins The terminal portion of the wall 17 that surrounds recess 15 is beveled on its outer face as djesi natcd by 18 and, as the ribbed portions ojtthe wall are thicker than those portions bet vcen the ribs, the beveling' of this end of the extractor provides short V shaped teeth or lugs 19 that project from the end portions of the ribs 16.

Formed through the body 10 of the tool a diametrically arranged aperture 20 that is-adapted to receive a pin or short rod and which later "functions as a handle that may be manually engaged when the tool is utilized for extracting the broken portion ofa tap (see Fig. 5). I

In the use of my improved extractor, the end of the hole in which the broken portion of the tap is embedded may be readilycountel-sunk orreamed out by placing'the tool in a drill press or the like and manipulat ing the same so that the teeth 14 engage the work *dircctlyadjacent the broken end of the tap as shown in Fig. 4:, and in a short time the work will be countersunk or cut away so as to leave a short. portion of the broken. tap projecting upwardly within thecenter of the countersunk portion.

- The extractor. is now removed from the drill press and after a pinor key has been inserted in aperture 20, the end of the tool provided with the teeth 19 is positioned over the projecting end of the broken tap withflsaid teeth 19 engaging those portions of the grooves in the tap that project into the countersunk portion of the workand by rotating the tool, the same will function as a'spanner wrench to unscrew and remove the broken portion of the tap. 7

Obviously the extractors contemplated by my invention may be made in various sizes to correspond with the standard sizes of taps and by the use of the extractors,"'much time andflabor may be saved in the removal of those portions of taps that break and remain in the work.

Thus itwill be seen that I have provided a broken tap extractor that is relatively simaid with ple in construction, inex )ensive of manufacture and Which-is very eflective in performing the functions for which it is intendeck It will be understood iJlIHlF-IHlIIOI changes in the size, form and construction of the various parts of my improved broken tap extractor may be made and substitutml for those herein shown and described without departing from the spirit of my invention, the scope of which is set. forth in the appended claims.

I claim as my invention:

L A. broken tap extractor comprising a short cylindrical body provided at one end with an axially arranged recess on the inner surface of which recess are formed longitudinally arranged tap groove engaging ribs, the outer ends of which terminate 1n tapered teeth that. proJect from thcend of the cylindri cal body.

2. A broken tap extractor comprising a 0 short cylindrical body provided at one end with an axially disposed. recess the end of the wall surrounding said recess being provided with a beveled face, and longitudinally ar ranged ta groove engaging ribs formed on 95 wall surrounding said recess being provided 39 with a beveled face, longitudlnally arri'mged tap groove engaging ribs formed on the inner {meet the recess in said body, and there being an aperture formed through the intermediate portion of the body of said extractor. 35

In testimony whereof I aiiix my signature.

DAVID PEARCE. 

